US drug giant Pfizer has defended its scientific track record ahead of a grilling from UK politicians this week.

Mikael Dolsten, president of Pfizer’s research and development (R&D), has pressed the pharmaceutical case for an acquisition of AstraZeneca in an attempt to allay concerns that a takeover of AstraZeneca would lead to severe cost-cutting and the erosion of British scientific innovation.

Mr Dolsten said in a video that appears on Pfizer’s website that he has been through five different mergers and acquisitions and has “come to appreciate how much you actually can learn”. The video, split into four sections, follows a video issued over the weekend featuring Pfizer boss Ian Read declaring a deal would be a "win win" for shareholders, stakeholders and society.

The R&D boss stopped short of making any guarantees that Pfizer would continue to invest in AstraZeneca’s new facilities in Cambrigdge, which the US company would then be forced to uphold for a year, however said that he was “really impressed with the Golden triangle – characterised by London, Oxford and Cambridge”.

“To see a combined company having a R&D presence with physical facilities and reaching out in biomedical networks to key investigators across many diseases in this U.K. area of biomedicine would be really inspiring, and I think it would create a very strong bridge to our global R&D activities and our strengths in biomedical hubs in US”

Mr Dolsten also denied that the large deal could be disruptive: “If you keep your sense of curiosity and an open mind, you can learn tremendously in your career during mergers processes”.

"We must stay laser-focused on our important projects. And that’s, of course, true for Pfizer scientists and AZ scientists and will be true also if we can make a potential combination come together," he said.

Mr Dolsten also emphasised Pfizer’s record on drug creation by saying that the company was working on 300 projects with more than 80 in clinical development as well as mid-stage drugs for the treatment of breast cancer, cholesterol management and meningitis B vaccines.

“A couple of years ago, we started R&D turnaround. It was a response of R&D to Ian Read’s first imperative of fixing the innovative core of the company. We have made great progress. We have created an intersection of science and business in the way we look upon how we select, prioritize and promote projects moving forward.”

The Pfizer executive also said that the two companies would be a "great fit" in therapeutic areas of oncology, inflammation, cardiometabolic diseases. "When I look at this transaction, of a potential combination of AZ and us, I get real excited thinking about what we could accomplish in accelerating the advance of science and medicine to the benefit of patients worldwide", Mr Dolsten said.

The videos come ahead of two separate House of Commons select committee meetings next week in which Mr Read and Pascal Soirot, his opposite number at AstraZeneca, will be grilled by politicians.

The duo are due to appear before the Commons business select committee on Tuesday. The following day the Science Committee, chaired by Andrew Miller, will question Mr Read and Mr Dolsten on the impact on the UK science industry by a potential takeover.

Although no firm offer is on the table - AstraZeneca rejected Pfizer's most recent £63bn indicative offer - MPs will be looking for assurances on jobs, future investment and the American company's commitment to the UK.